21,19,17,15,13, is this sequence geometric or arithmetic

A geometric sequence is one where there is a common multiplied or divided ratio throughout each term.

An arithmetic sequence is one where there is a common added or subtracted difference throughout each term.

So, knowing this, I would say that this sequence is an arithmetic sequence.

Hope I helped!

$25

step-by-step explanation:

25 - 4.50 = 20.5

20.5 / 2 = 10.25

10.25 + 10 = 20.25

20.25 - 12.50 = 7.75

therefore the answer is $25 as shown as the first number.

a

step-by-step explanation: